Wrist: Current Diagnosis and Treatment of Scaphoid Fractures and Injuries of the Scapholunate Ligament

Summary BACKGROUND: Fractures of the scaphoid and injuries to the scapholunate ligament are mostly seen as causes of the acute and chronic painful wrist. Strict guidelines are necessary to precisely detect these lesions in the acute stage and to provide adequate treatment. A computed tomography bone scan parallel to the long axis of the scaphoid is best for demonstrating fractures and any associated deformities. Scapholunate ligament injuries are best staged by standard plane radiographs including stress views and by arthroscopy of the wrist. METHODS: To avoid lengthy plaster immobilization and to lower the risk of nonunion, displaced and comminuted scaphoid fractures of the wrist as well as all proximal pole fractures should be internally fixed. Headless screws such as the Herbert screw, now available in a cannulated shape, allow the minimally invasive stabilization of the majority of these fractures with a high success rate under early mobilization. Undisplaced fractures can be treated conservatively with a below-elbow cast; alternatively, they can be stabilized percutaneously without the need for immobilization in a cast. Early diagnosis of scapholunate ligament injuries is most important, as anatomical healing of the injured ligaments can be expected only with primary treatment including correct realignment of the scaphoid and lunate followed by immobilization in a cast for about 8 weeks. In cases of chronic lesions, ligament reconstruction or even partial wrist fusion can be performed. In order to assess the different procedures, precise classification and staging with regard to a dynamic or static pattern are needed. RESULTS: Early rigid fixation of scaphoid fractures promotes a union rate of up to 100 % with rapid functional recovery. Primary repair of scapholunate ligament injuries provides the best clinical outcome. Ligament reconstruction or partial wrist fusion can help to prevent rapid secondary arthrotic changes in the wrist and leads to significant pain relief, however with restriction of mobility and grip strength. CONCLUSIONS: Standardized diagnosis and treatment of scaphoid fractures and scapholunate ligament injuries improve clinical outcome and significantly reduce post-traumatic arthrotic changes in the wrist.